Control mechanism



Nav. 6, 1928. I' 1,690,847

w. l. TwoMBLY CONTROL MECHANISM Filed June 6. 1922 2 Sheets-Sheet i l ES LOIN L.

Nov. 6, 1928*.

W. l. TWOMBLY CONTROL MECHANISM Filed June 6. 1922 2 Sheets-Sheet 2 INVENTOR.

WMQJM ATTORNEY.

Patented Nov. 6,1928..

UNITED STATES PATENT OFFICE. f

i WILLARD I. lI-LWOMBLY, 0F NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE WILCOLATER COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION 0F DELAWARE.

CONTROL MEOHANISM.'

Application med/ :une c,

This invention relates to apparatus for controlling the supply of fuel to fuel-consuming devices, .and more specifically has to do with control mechanism by which the flow of fuel to burners may be controlled so that a relatively constant predetermined temperature may be maintained in a chamber heated by the burners for a predetermined length of time. This mechanism is particularly adapted for use in connection with gas stoves having an Oven chamber.

Heating devices of this kind have heretofore been provided with regulators which operate to control the iow of fuel so that a constanttemperature in a chamber is maintained throughout a given period of time, but these regulators have not been designed primarily for the purpose of producing a compact, easily operated, enclosed device. The clock mechanism by which the flow of fuel is controlled for a given period of time is located at one point in the fuel line, while the temperature control maybe located at another. Devices of thisv sort are consequentlyl not suitable for use in gas stoves where convenience of operation is of great importance and where economy of space must also be emphasized. The present invention is directed to the provision of a device which is compact and occupies little space, and which is also readily operated, with the elements by which the device is set placed conveniently for the operator. The device includes a pair of cas-I ings, separated by a common partition wall in which is a passage provided with a valve. This valve is normally ybiased toward the closed position, and a clock mechanism is mounted in one of the casings and arranged so that when the valve has been manually set in open position it is locked there by suitable means which are released by the clock mechanism after a predetermined lapse of time. -The gas flows into the casing which contains the clock mechanism, passes through the valve when the latter is open, into the second casing in which is a thermostatic control device, including a valve through which the gas flows to an outlet to the burner. This control device includes an element which is responsive to temperature changes and is placed in the chamber heated by the burner. vThe gas flowing from the first casing into the second,

1922. Serial No. 566,424.

Hows out through theburner under the control of the thermost'atically operated valve. The clock mechanism is set by a lever placed on the firstV casing, and a setting device for the thermostatic mechanism is placed on the second casing, so that the t-wo setting devices may be conveniently manipulated.

In the accompanying drawings there is shown one form of the invention which is found to -be satisfactory, and in these drawings Fig. 1 is a v iew showing in'side elevation one form of apparatus embodying my invention. Fig. 2 is a horizontal sectional view on the line 242 of Fig. 1, and F ig. 3 is a vertical sectional view on the line 3 3 of Fig. 2.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig/s. 1, 2 and 3, the reference character F designates a casing apertured at one end to receive a pipe 12, which may be connected with a source of gas or other fuel. The opposite end of the casing F constitutes a wall 10, provided with a port 11, in which is interposed a manuallyv operable valve D. This valve is biased to the closed position by a spring 38, one end of which is anchored to the casing F, and the other end of which is attached to the stem of the valve D. This valve is provided with a handle 39, by which it may be opened manually in opposition to the force exerted by the spring 38.

In order to lock the valve D in the open position I. provide the stem of this valve with a hole or recess14, and I also provide a pin 15 which may be moved into and out of the recess 14. The hole 14 and the pin 15 are so located that when the valve D is open the pin may be projected into the hole to keep the valve open; obviously when -the pin is subsequently withdrawn from the hole in the valve stem the valve will close under the influence of the spring 38.

The pin 15 is pivotally attached to a plate 16 which is mounted to rock on 'a stud 17 fixed in a bracket 19, which latter is attached to a plate 23 mounted in the casing F. The stud 17 carries a spring 18, one end of which is fixed to the stud and the other end of which bears againstv4 the rocker plate 16, the effect of this spring being to bias the plate.16 in such direction as to project the pin 15 intoJthe hole 14 in the stem of valve D. The plate 16 may be rocked in the other direction by a nut 40 which travels on the threaded end 21 of a shaft 20. That is to say, the left hand end of the plate 16 as viewed in Fig. 2 is apertured to surround the flanged nut 40, sothat when the shaft 20 is turned in such direction as to draw the nut inwardly, the plate 16 is rocked in opposition to the spring 18 and thereby operated to withdraw the pin 15 from the hole 14.

The shaft 20 is journaled in the plate 23, and also in the front wall of the casing F, and the shaft projects through the front wall of the casing to receive a. key 22 by which the shaft may be turned by hand.

Associated with the shaft 2O is a clock work mechanism H comprising a main spring 24, one end of which is attached to the'J plate 23, and the other end to the shaft itself, which spring tends to rotate the shaft in such direction as to draw the nut 40 inwardly to release the valve D. Such rotation of the shaft 2O is restrained however, by the remainder of the clock work mechanism H, comprising a gear 41 loosely mounted on-Lthe shaft 2O and carrying a spring-pressed pawl 41 engaging the teeth of a ratchetwheel 41a secured to -the shaft, a train of gears 26 and 27, an escapement wheel 28, a pallet 42 and a hair spring 2Q. The operation of the parts thus far described is as follows:

In order to set the device for a given interval of time the valve D is first opened by hand. and the key 22 is then turned to the proper point, thereby permitting the pin 15 to enter the hole 14. The valve D is then locked in theopen position and the clock work mechanism H immediately begins to turn the shaft 20 in such direction as to draw the nut 40 inwardly, thereby gradually withdrawing the vpin 15 from its locking position. At the expiration of the given interval of time this -pin is fully withdrawn, whereupon the valve D closes under the intluence of its controlling spring 3S and so the supply of `fas is discontinued.

The front face of the casing F is provided with a dial 3T, the circumference of which is divided into 12 spaces each representing a time interval of 5 minutes. and apointer 36 is attached to the shaft 20 and arranged to move over the dial. The clock work mechanism H is so designed that a period of one hour will be required to move the pointer 36 around the entire circumference of the dial 37; in other words. one complete revolution of the shaft 20 consumes one hour. Thus if, when the valve is locked in the open position in the manner which has been described, the key 22 and pointer 36 are moved counter-clockwise two full revolutions. the valve will open at the end of two hours.

TVhen the pointer 36 is opposite the 60" mark on the dial. the nut 40 is in such position that pin 15 is withdrawn'from the hole 14. Upon turning the shaft 2O to the right,

as viewed in Figure l the nut 40 will be moved to lock the valve D and the angular displacementof the shaft as measured by the position of the pointer 36 on the dial 3T will be a measure of the time interval required to again release the valve D.- Thus.

'11 includes a chamber 30, a passageway 31,

a valve 43 and a port 32 leading into the nipple 13. The valve 43 is controlled by a thermostat device designated as a whole by the reference character Gr which device is disclosed and vclaimed in my Patent- No. 1.616,419, granted Feb. 8, 1927, for controls for regulating temperature.

Briefly described. the device G comprises a bellows 33 controlling the position of the valve 43, and which bellows in turn is controlled by the pressure of gas in a bulb 34, which is placed in the chamber to be heated. As explained in my patent referredwto above. the thermostatic device G may be adjusted to maintain any desired constant temperature within the oven or other chamber which is heated by the gas supplied from the nipple 13. The mechanism of the automatic temperature control forms no part of my pre`sent. invention and so is not fully described.

It will be seen from the foregoing that by l virtue of the combined thermostat and time control I am enabled to maintain the temperature in the Qven at any desired constant value for any. desired interval of time.

Although I have stated that in the form here shown the thermostatic device G is the same as that described and claimed in mv patent above mentioned, it is understood that rotate in the opposite direction, clockwork mechanism for restraining the rotation of said shaft in response to its biasing force,

a traveller nut coacting with the threads` on said shaft, and means controlled by the.

travel of said nut on its shaft for locking said device in open position.

2. In combination, a threaded shaft biased to rotate in one direction and rotatable freely in the opposite direction, clockwork mechanisrn for restraining rotation of said shaft in response to its bias, a traveller nut co` acting withJ the threads on said shaft, a de# vice biased to the closed position for admitting fuel to a fuel-consuming element, a pin coacting with a recess in said deviceto lock the device in open position, meansfor biasing said pin to locking position in its recess, and a connection between said nut and said pin for withdrawing the pin as the nut travels along said shaft due to 'rotation of the shaft in response to its bias.

WILLARD I. TWOMBLY. 

